Rabol 2009 Metabolism

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Rabøl R, Svendsen PF, Skovbro M, Boushel RC, Haugaard SB, Schjerling P, Schrauwen P, Hesselink MK, Nilas L, Madsbad S, Dela F (2009) Reduced skeletal muscle mitochondrial respiration and improved glucose metabolism in nondiabetic obese women during a very low calorie dietary intervention leading to rapid weight loss. Metabolism 58:1145-52.

» PMID: 19454354

Rabol R, Svendsen PF, Skovbro M, Boushel RC, Haugaard SB, Schjerling P, Schrauwen P, Hesselink MK, Nilas L, Madsbad S, Dela F (2009) Metabolism

Abstract: Reduced oxidative capacity of skeletal muscle has been proposed to lead to accumulation of intramyocellular triglyceride (IMTG) and insulin resistance. We have measured mitochondrial respiration before and after a 10% low-calorie–induced weight loss in young obese women to examine the relationship between mitochondrial function, IMTG, and insulin resistance. Nine obese women (age, 32.3 years [SD, 3.0]; body mass index, 33.4 kg/m2 [SD, 2.6]) completed a 53-day (SE, 3.8) very low calorie diet (VLCD) of 500 to 600 kcal/d without altering physical activity. The target of the intervention was a 10% weight loss; and measurements of mitochondrial respiration, IMTG, respiratory exchange ratio, citrate synthase activity, mitochondrial DNA copy number, plasma insulin, 2-hour oral glucose tolerance test, and free fatty acids were performed before and after weight loss. Mitochondrial respiration was measured in permeabilized muscle fibers using high-resolution respirometry. Average weight loss was 11.5% (P < .05), but the levels of IMTG remained unchanged. Fasting plasma glucose, plasma insulin homeostasis model assessment of insulin resistance, and insulin sensitivity index (composite) obtained during 2-hour oral glucose tolerance test improved significantly. Mitochondrial respiration per milligram tissue decreased by approximately 25% (P < .05), but citrate synthase activity and mitochondrial DNA copy number remained unchanged. Respiratory exchange ratio decreased from 0.87 (SE, 0.01) to 0.79 (SE, 0.02) (P < .05) as a sign of increased whole-body fat oxidation. Markers of insulin sensitivity improved after the very low calorie diet; but mitochondrial function decreased, and IMTG remained unchanged. Our results do not support a direct relationship between mitochondrial function and insulin resistance in young obese women and do not support a direct relationship between IMTG and insulin sensitivity in young obese women during weight loss.


O2k-Network Lab: DK Copenhagen Dela F, SE Stockholm Boushel RC, NL Maastricht Schrauwen P, CA Vancouver Boushel RC, DK Copenhagen Larsen S


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Organism: Human  Tissue;cell: Skeletal muscle  Preparation: Permeabilized tissue 

Regulation: Fatty acid 


HRR: Oxygraph-2k